The bus was returning to Budapest from France, where the students had been on a mountain holiday.

Some 36 injured people were taken to a hospital following the accident near Verona on Friday night.

"Many children among the victims of the accident in Verona, a bus catches fire on impact with a pillar," national police said on Twitter.

Police commander Geralomo Lacquaniti said the bus crashed and burst into flames just before midnight. No other vehicles were involved and it was not clear why the bus went off the road, crashing into the barriers.

Lacquaniti said the cause of the crash would be investigated. "We are not aware of other vehicles being involved, it seems to have gone off the road of its own accord."

He said some people had minor injuries, but others were more serious.

The French bus driver, together with his family, could be among the victims, Italian news agency Agi said.

It was carrying about 50 passengers, most of whom were Hungarians aged between 16 and 18. Police say 16 badly burned bodies have been pulled from the wreckage.

The report said some students were thrown from the vehicle and others were trapped inside the bus when it caught fire.

Police were awaiting the go-ahead from the prosecutor to analyse the charred remains of the vehicle.